I purchased a 2001 Beetle diesel (1.9 ) lightly wrecked. I replaced the intercooler and built all the hoses out of plastic water pipe (pvc) . Comes out 1" and goes to 2". I was told this was ok to do. The engine light is not on. The engine starts and runs great, idles perfect but is really sluggish , has no get up and go at all. No black smoke, no rough running, it just will not go. You can floor it and it just gradually gains speed, it takes two miles to get to 50mph. Please help. Thanks